I don't have an answer for the
(or even for the
), but I once had a temporary dock line tied to a lifeline while in a navigation lock, with the water rising. The line got jammed at the top of the static line you run your line around to hold the boat close to the wall, and the boat started tipping as the water was coming up. I had my super sharp rigging knife with me, and cut it real quick, resulting in a bunch of embarrassing rock-n-roll, and a bit of a bend in the lifeline stanchion. But not enough make me want to replace it. But it sure was scary with the boat slowly rolling and no lock operator in sight.
The life line stanchions are soft - I found out the first day I brought the boat home because I needed to cut one of the starboard ones to get the boat into the new driveway (it was hitting the garage eaves) and I was surprised how easily it cut with a pipe cutter - like ten turns around the pipe and, WHAM! pipe cut! So I went to West Marine to get a sleeve pipe to put on the inside so I could slide the two pieces back together and they just happened to have the very same stainless style pipe that was used on the boat, and they had it in different sizes too! They had the size that fit perfectly INSIDE the original so that I could piece the two cut pieces back together and with the sleeve inside it performed just like it did when it was whole - only now I could remove the top part when needed by just removing the tension line. Others here taught me that the soft stanchions are designed to resist corrosion so they are soft - the cleats are better for dock ties - and they are stronger than the stanchions.
SO - long story short - you can buy replacement pipe and try to fix it that way OR as i would recommend go below decks and start cutting away the liner under there and remove the foam and get out the nuts. Then when you are done you can repair the liner where you cut it - or put in a hatch as previously suggested.
Another option is to buy the hole plugs from BWY that are used on the liner to access nuts - then you could put in your own access holes and plugs.